Channel 17 first signed on the air on June 17, 1960, as WPCA-TV, the call letters standing for "People's Church of the Air."[4][5]Founded by Percy Crawford, it originally maintained a religious programming format.[6] WPCA was Philadelphia's first commercial UHF station; however, the station suffered due to the fact that UHF tuners were not required to be incorporated onto most television sets at the time (the Federal Communications Commission (FCC) would not make UHF tuning capability a requirement until 1964 with the passage of the All-Channel Act), WPCA shut down on August 1, 1962 after only being on the air for two years.

Subsequently, advertising executive Len Stevens and attorney Aaron Katz formed Philadelphia Television Broadcasting Company which purchased the channel 17 license and returned it to the air on September 17, 1965 as independent stationWPHL-TV.[7][8][9][10]It was the third UHF independent to sign-on in Philadelphia that year, two and a half weeks after WKBS-TV (channel 48) and four months after WIBF-TV (channel 29, later WTAF and now WTXF-TV). After merging with U.S. Communications Corporation in 1967 WPHL-TV became the flagship station for their station group.[11][12][13][14] U.S. Communications also operated WATL-TV in Atlanta, WPGH-TV in Pittsburgh, WXIX-TV in Cincinnati and KEMO-TV now (KOFY-TV) in San Francisco. The station produced and aired numerous local television shows over the years, including kids' favorite Wee Willie Webber's Colorful Cartoon Club and Dr. Shock's Horror Theater.[15]

In the summer of 1975, WPHL-TV moved from its original studio facility at 1230 East Mermaid Lane in the suburb of Wyndmoor to its current studio on Wynnefield Avenue in the Wynnefield suburb of West Philadelphia. The building had once been the location of an A&P supermarket. The station offered a schedule of off-network drama series, sitcoms, old movies, sports and religious programs. It also ran NBC and ABC programs that KYW-TV (channel 3, now a CBS owned-and-operated station) and WPVI-TV (channel 6) had respectively pre-empted until the fall of 1976, and again from the fall of 1977 to the summer of 1983. The Providence Journal Company bought channel 17 in 1979. At that point, WPHL sought a different programming strategy geared towards adults, gradually dropping children's programming and cartoons. It focused more on movies, off-network drama series, recent off-network sitcoms and sports. The station also aired several hours of religious programming each day.

Throughout the late 1970s and 1980s, WPHL was known on-air as "The Great Entertainer," with voiceovers provided by announcer Sid Doherty. The station positioned itself as an alternative to both WTAF and WKBS, as it programmed more towards adults with movies and other syndicated programs, while its competitors were heavy on sitcoms and children's cartoons. WPHL was also a station heavy on local sports, as it aired games featuring Major League Baseball's Philadelphia Phillies until 1982, the NBA's Philadelphia 76ers from 1982 to 1995 and the NHL's Philadelphia Flyers in the 1990s.

In the summer of 1982, WKBS went on the market after its owner, Field Communications, decided to exit broadcasting. The Providence Journal Company was among those who were bidding for channel 48's license. Had it won, Journal would have merged WPHL's and WKBS' schedules under the WKBS license and channel allocation, while selling the channel 17 license to either a religious or educational broadcaster. However, the Journal Company's bid was still far below Field's asking price. With no takers willing to give Field what it wanted for the station, WKBS-TV ceased operations one year later on August 29, 1983, and WPHL picked up various syndicated programs, cartoons, movies and production equipment from WKBS.

In 1987, the Providence Journal Company sold WPHL-TV to a consortium headed by Dudley S. Taft Jr., the former president of the Cincinnati-based Taft Television and Radio Company, the longtime owners of rival WTAF-TV. Dudley Taft had left his family's namesake company following a corporate restructuring which resulted in the firm changing its name to Great American Broadcasting. He also brought along key personnel from WTAF (which Taft had sold to TVX Broadcast Group in early 1987), including general manager Randy Smith. The new ownership scrapped the "Great Entertainer" slogan and related logo for a new identity as "PHL 17", in an apparent attempt to counter WGBS-TV's (channel 57, now WPSG) "Philly 57" branding. The new owners restored some cartoons to the schedule. In 1991, the Taft group sold channel 17 to the Tribune Company.

On November 2, 1993, Tribune and the Warner Bros. Television division of Time Warner announced the formation of The WB Television Network. Due to the company's minority interest in the network (initially 12.5%, before expanding to 22%), Tribune chose to affiliate the majority of its independent stations with the upstart network, resulting in WPHL-TV becoming a network affiliate for the first time in its history upon The WB's January 11, 1995 debut.[16][17] In September of that year, the station changed its on-air identity to "WB 17". For most of The WB's run, WPHL was one of the network's strongest affiliates.

On January 24, 2006, CBS Corporation (which split from Viacom in December 2005) and Time Warner's Warner Bros. Entertainment (the division that operated The WB) announced that they would dissolve UPN and The WB and merge both networks' stronger programming onto a newly created network, The CW. Concurrent with the announcement, it signed a ten-year affiliation agreement with 16 of Tribune's 19 WB-affiliated stations.[18][19] However, in the case of Philadelphia, The CW's affiliation went to the city's UPN station, CBS-owned WPSG (which was part of an affiliation deal with 11 of CBS' UPN stations). It would not have been an upset had WPHL been chosen as the area's CW affiliate, however. The network's officials were on record as preferring The WB and UPN's "strongest" stations for their new network, and Philadelphia was one of the few markets where the affiliates of both networks were both relatively strong.

WPHL was slated to revert to its previous independent status, but on May 15, 2006, Tribune announced that it would affiliate channel 17 (and two other WB affiliates that were not included in the CW affiliation deal) with MyNetworkTV, making WPHL the largest station in terms of market size affiliated with the network that was not owned by its then-parent company News Corporation (which became 21st Century Fox in June 2013 after spinning off most of its non-entertainment properties). It is also the only major station in Philadelphia that is not owned by its respective network. In July, WPHL rebranded itself as "MyPHL17", reviving the station's former "PHL 17" moniker. WPHL began airing MyNetworkTV programming on the day that the new service was launched, September 5, 2006. As a result, it did not air the final two weeks of The WB's programming.

On October 4, 2010, the station removed the "My" portion of the branding as many affiliates of the network began dropping references to MyNetworkTV due to it becoming more of a primetime programming service than a true television network. WPHL retains the multi-shaded 'blue TV' component of the network's logo as part of the station's own logo. Before the move of the broadcast rights of the Phillies in 2014 to WCAU-TV, another version of the logo was used where the "p" in "phl" was replaced with the hat insignia "P" from the logo of the Philadelphia Phillies. In addition, the Antenna TV subchannel the station carries is branded with a modified version of their 1970s/80s "Great Entertainer" logo; many other Antenna TV stations do this as well.

On May 8, 2017, Sinclair Broadcast Group announced that it would acquire Tribune Media for $3.9 billion, plus the assumption of $2.7 billion in debt held by Tribune. However, on August 9, 2018, Tribune announced that it had pulled out of the deal, after the FCC raised "serious concerns" about the amount of money some of the stations being resold in the deal were being sold for.[21]

Throughout the station's three of its first four decades on the air, WPHL had a tremendous professional sports presence—at various points holding the broadcast rights to the Phillies (1971–82 and 1993–98, and through the production of Comcast SportsNet Philadelphia from 2009 to 2013; as of 2014[update], WPHL airs overflow Phillies games when both CSN Philadelphia and primary overflow outlet Comcast Network are carrying other games and present over-the-air carrier WCAU is preoccupied by NBC network commitments), the Flyers (1991–98) and the 76ers (1982–95), as well as covering local college basketball and football, with games featuring teams from the Philadelphia Big 5 (La Salle Explorers, Penn Quakers, Saint Joseph's Hawks, Temple Owls and Villanova Wildcats). After the station joined The WB, it released many of its sports contracts in order to concentrate on its network programming obligations.

The station aired syndicated college football and basketball games from the syndication arm of ESPN involving the Mid-American Conference (football, owing to Temple being a football-only member of the league) and Big East Conference (basketball) until 2009, when WPVI took over rights. WPHL also aired Big Ten Conference games (owing to Penn State's large fan base in the area) until the creation of the Big Ten Network on cable in 2007.

WPHL has aired preseason games of the NFL's Philadelphia Eagles. Also, it usually wins the rights to air one or two regular season Eagles games on Monday nights, due to the NFL's anti-siphoning rule requiring games airing on cable to be available on an over-the-air station in each team's home market; by rule, the NFL sells syndication rights of local teams' games. The station's news partner, WPVI-TV, has the right of first refusal on Monday night games due to its parent company (Disney) being majority owner in ESPN, but generally defers in order to air Dancing with the Stars (due to the program's popularity and the structure of its live voting requirements) during that program's fall season.

In 1994, WPHL entered into an agreement with local daily newspaper The Philadelphia Inquirer to broadcast an Inquirer-branded primetime news program. The half-hour Inquirer News Tonight was a hybrid newscast that integrated the conventions of a typical television news program with contributions from the newspaper's personnel. However, the format failed to make any headway against WTXF's established primetime newscast; behind-the-scenes issues with Knight-Ridder (the Inquirer's owner at that point), including newspaper staffers' wariness of being on TV and compensation and contract issues, as well as general mismanagement, doomed the program.[23] Another blow occurred in October 1995 when weekend weatherman Bill Elias was fired following the revelation of his involvement with a local crime family (he had given mob boss John Stanta's bodyguards a videotape of a mob funeral in 1993, to pick targets from another crime family to kill); he had previously lost his job at WTXF over this.[24] WPHL took full control of the newscast, changing to the WB 17 News at Ten in late 1996.

Even after WPHL took its newscast in-house, it still remained far behind WTXF in the ratings. In the fall of 2005, WPHL announced that its news department would be shut down; the final 10 p.m. newscast produced by WPHL aired on December 9, 2005. The following day, production of the 10 p.m. newscast was turned over to NBCO&O WCAU through a news share agreement. This newscast was partially renamed to WB 17 News at 10, Powered by NBC 10. On July 25, 2006, the program was renamed My PHL 17 News, Powered by NBC 10 to correspond with WPHL's upcoming switch to MyNetworkTV. On December 10, 2008, WCAU began broadcasting its local newscasts in high definition, and the WPHL newscast was also included in the HD upgrade. The newscast was renamed once again on October 4, 2010 as phl17 News at 10, Powered by NBC 10.

On October 31, 2011, WPHL began airing EyeOpener, a morning news program concept by Tribune Broadcasting that originally debuted in May 2011 on Houston sister station KIAH, featuring a mix of news, lifestyle, entertainment and opinion segments. Local news, weather, and traffic segments are featured along with local reports presented by five multimedia journalists; however, much of EyeOpener (which was previously produced at Tribune Company's Chicago headquarters) is pre-produced at the studios of Dallas-Fort Worth sister station KDAF and is also distributed on Tribune-owned stations in three other markets that provide their own localized content.[25][26]

The WCAU-produced 10 p.m. newscast ended on September 14, 2012, and WPVI-TV took over production of the newscast the following day through a news share agreement with the ABC owned-and-operated station. Accordingly, the newscast was renamed Action News at 10 on PHL17. The weekday editions of the newscast utilize the same anchor team seen on WPVI's 4 p.m. newscast, while the weekend newscasts use the same staff as that station's weekend evening newscasts.[27] It is the third ABC owned-and-operated station to be involved in a news share agreement, following KGO-TV in San Francisco (which produces independent station KOFY-TV's 9 p.m. newscast) and WTVD in Durham (which produces CW affiliate WLFL's 10 p.m. newscast), and was later joined in 2014 by KABC-TV in Los Angeles (which produces independent station KDOC-TV's 7 p.m. newscast). On September 8, 2014, the newscast was expanded to an hour.[28]

On March 9, 2015, WPHL launched a half hour 5:30 a.m. newscast produced independently called The PHL17 Morning News. It is the first in-house newscast since the closure of their former news department at the end of 2005. The station's news studio was rebuilt, and the tri-caster formerly used was replaced with switchers, along with other equipment. The team then started producing independent news reports for the Delaware Valley.

In Pennsylvania, WPHL is carried on Comcast cable systems in Harrisburg, York and Lancaster; however, it is not available in high definition. It has been available on South Central Pennsylvania cable systems for four decades; indeed, for most of The WB's run, it was that market's default WB affiliate (the network's programming aired in off-hours on local station WPMT). It is also carried in Milford, Pike County (which is part of the New York City television market). In Maryland, WPHL is carried on cable in Cecil County.

In New Jersey, WPHL is carried in parts of Hunterdon, Middlesex, Monmouth, Somerset and Warren counties. It is available on Cablevision's analog service on its systems in Ocean and Monmouth counties. On Comcast in Ocean and southern Middlesex counties, WPHL is available in standard definition on digital cable 255. Comcast had carried the station on analog channel 17 until February 2008, when it was moved to digital only to "preserve bandwidth"; Comcast added WPHL's HD signal to its lineups in Ocean and Southern Middlesex counties, the borough of Roosevelt in Monmouth County and Lambertville in Hunterdon County on August 22, 2012 on digital channel 907. WPHL's Antenna TV, This TV (both were already carried as subchannels of WPIX) and Tango Traffic (now GeoTraffic) subchannels were added to the provider's Southern Middlesex County system on November 27, 2012 (found with a rescan of a digital tuner) but have not been mapped into the Comcast digital boxes or DTAs. There is no satellite coverage of WPHL outside of the Philadelphia market.

During the 1970s and 1980s, WPHL was a regional superstation available in New York City and portions of Long Island,[29] as well as the large majority of New Jersey. In New Jersey, WPHL was carried on alongside competitors WTAF, and until it shut down in 1983, WKBS.[29] The station was also carried on Comcast on the former Adelphia system in the suburbs of Scranton until replaced with a local affiliate.